Hefting the hive,

[Finman]

Before I do the oxalic acid drip in winter I check a few colonies to reassure myself there is no brood. I have noticed that there are many bees in the cluster occupying empty cells head down in the cell. This is also described by Thomas Seeley in his book "honeybee ecology" page 112. I suggest that areas of empty cells in the comb are indeed important in clustering and temperature control.

I have seen too with my own eyes but when cells are full at the beginning, because I feed them full.

Perhaps you have noticed, that there is a long Autumn between summer and winter, and bees consume food too in autumn

We have about 3 months long autumn, before we get permanent snow. At the beginning of december we use to have permanent snow in South Finland. After that I put geo construction textile over hives.

Big colonies consume 1-1.5 kg food in one month in autumn.